An award-winning journalist, killed by a car bomb in Kyiv, has been laid to rest in his native Belarus.

Mourners gathered to lay flowers on Pavel Sheremet’s grave and at a church in Minsk.

Ukraine’s President Petro Poroshenko has described his death as an attempt to destabilise the country. Some say it is an attack on free speech.

“We can take this to mean that strong and honest journalists are not wanted in any country,” said Ihar Rynkievic, from the Belarussian National Platform.

“Whichever basic versions of the crime will be proven, for us this almost political execution in the centre of Kyiv is a signal that journalists are in the cross hairs.”

Sheremet was known for his criticism of Belarus’ leadership, his friendship with Russian opposition leader Boris Nemtsov – who was murdered last year – and his work for a Ukrainian investigative website.

He was driving to work in the car of the site’s owner when it was blown up.

Poroshenko asked experts from the US Federal Bureau of Investigation on Wednesday to join the murder investigation in the interests of “maximum transparency.”

In a statement, the US State Department expressed shock at the killing and said the FBI had begun to assist Ukrainian authorities in their investigations.

Earlier, senior Interior Ministry officials said they could not rule out Russian involvement in the murder.